﻿using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;

namespace Koumi.Tools
{
    /// <summary>
    /// 验证码
    /// </summary>
    public class VerifyCode : System.Web.UI.Page
    {
        private int _length;
        private int _fontsize;
        private int _padding;
        private bool _chaos = true; 

        #region 验证码长度(默认6个验证码的长度)
        /// <summary>
        /// 验证码长度(默认6个验证码的长度) 
        /// </summary>
        public int Length
        {
            get { return _length; }
            set { _length = value; }
        }
        #endregion

        #region 验证码字体大小(为了显示扭曲效果，默认40像素，可以自行修改)
        /// <summary>
        /// 验证码字体大小(为了显示扭曲效果，默认40像素，可以自行修改)
        /// </summary>
        public int FontSize
        {
            get { return _fontsize; }
            set { _fontsize = value; }
        }
        #endregion

        #region 边框补(默认1像素)
        /// <summary>
        /// 边框补(默认1像素)
        /// </summary>
        public int Padding
        {
            get { return _padding; }
            set { _padding = value; }
        }
        #endregion

        #region 是否输出燥点(默认不输出)
        /// <summary>
        /// 是否输出燥点(默认不输出)
        /// </summary>
        public bool Chaos
        {
            get { return _chaos; }
            set { _chaos = value; }
        }
        #endregion

        #region 输出燥点的颜色(默认灰色)
        /// <summary>
        /// 输出燥点的颜色(默认灰色)
        /// </summary>
        Color _chaoscolor = Color.LightGray;
        public Color ChaosColor
        {
            get { return _chaoscolor; }
            set { _chaoscolor = value; }
        }
        #endregion

        #region 自定义背景色(默认白色)
        /// <summary>
        /// 自定义背景色(默认白色)
        /// </summary>
        Color _backgroundcolor = Color.White;
        public Color BackgroundColor
        {
            get { return _backgroundcolor; }
            set { _backgroundcolor = value; }
        }
        #endregion

        #region 自定义随机颜色数组
        /// <summary>
        /// 自定义随机颜色数组
        /// </summary>
        Color[] _colors = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };
        public Color[] Colors
        {
            get { return _colors; }
            set { _colors = value; }
        }
        #endregion

        #region 自定义字体数组
        /// <summary>
        /// 自定义字体数组
        /// </summary>
        string[] _fonts = { "Arial", "Georgia" };
        public string[] Fonts
        {
            get { return _fonts; }
            set { _fonts = value; }
        }
        #endregion

        #region 自定义随机码字符串序列(使用逗号分隔)
        /// <summary>
        /// 自定义随机码字符串序列(使用逗号分隔)
        /// </summary>
        string _codeserial = "0,1,2,3,4,5,6,7,8,9";//,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
        public string CodeSerial
        {
            get { return _codeserial; }
            set { _codeserial = value; }
        }
        #endregion

        #region 产生波形滤镜效果
        private const double PI = 3.1415926535897932384626433832795;
        private const double PI2 = 6.283185307179586476925286766559;
        /// <summary>
        /// 正弦曲线Wave扭曲图片
        /// </summary>
        /// <param name="srcBmp">图片路径</param>
        /// <param name="bXDir">如果扭曲则选择为True</param>
        /// <param name="dMultValue">波形的幅度倍数，越大扭曲的程度越高，一般为3</param>
        /// <param name="dPhase">波形的起始相位，取值区间[0-2*PI)</param>
        /// <returns></returns>
        public System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)
        {
            System.Drawing.Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height);
            // 将位图背景填充为白色
            System.Drawing.Graphics graph = System.Drawing.Graphics.FromImage(destBmp);
            graph.FillRectangle(new SolidBrush(System.Drawing.Color.White), 0, 0, destBmp.Width, destBmp.Height);
            graph.Dispose();
            double dBaseAxisLen = bXDir ? (double)destBmp.Height : (double)destBmp.Width;
            for (int i = 0; i < destBmp.Width; i++)
            {
                for (int j = 0; j < destBmp.Height; j++)
                {
                    double dx = 0;
                    dx = bXDir ? (PI2 * (double)j) / dBaseAxisLen : (PI2 * (double)i) / dBaseAxisLen;
                    dx += dPhase;
                    double dy = Math.Sin(dx);
                    // 取得当前点的颜色
                    int nOldX = 0, nOldY = 0;
                    nOldX = bXDir ? i + (int)(dy * dMultValue) : i;
                    nOldY = bXDir ? j : j + (int)(dy * dMultValue);
                    System.Drawing.Color color = srcBmp.GetPixel(i, j);
                    if (nOldX >= 0 && nOldX < destBmp.Width
                     && nOldY >= 0 && nOldY < destBmp.Height)
                    {
                        destBmp.SetPixel(nOldX, nOldY, color);
                    }
                }
            }
            return destBmp;
        }
        #endregion

        #region 生成校验码图片
        /// <summary>
        /// 生成校验码图片
        /// </summary>
        /// <param name="code"></param>
        /// <returns></returns>
        public Bitmap CreateImageCode(string code)
        {
            int fSize = FontSize;
            int fWidth = fSize + Padding;
            int imageWidth = (int)(code.Length * fWidth) + 4 + Padding * 2;
            int imageHeight = fSize * 2 + Padding;
            System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth, imageHeight);
            Graphics g = Graphics.FromImage(image);
            g.Clear(BackgroundColor);
            Random rand = new Random();
            //给背景添加随机生成的燥点
            if (this.Chaos)
            {
                Pen pen = new Pen(ChaosColor, 0);
                int c = Length * 10;
                for (int i = 0; i < c; i++)
                {
                    int x = rand.Next(image.Width);
                    int y = rand.Next(image.Height);
                    g.DrawRectangle(pen, x, y, 1, 1);
                }
            }
            int left = 0, top = 0, top1 = 1, top2 = 1;
            int n1 = (imageHeight - FontSize - Padding * 2);
            int n2 = n1 / 4;
            top1 = n2;
            top2 = n2 * 2;
            Font f;
            Brush b;
            int cindex, findex;
            //随机字体和颜色的验证码字符
            for (int i = 0; i < code.Length; i++)
            {
                cindex = rand.Next(Colors.Length - 1);
                findex = rand.Next(Fonts.Length - 1);
                f = new System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold);
                b = new System.Drawing.SolidBrush(Colors[cindex]);
                if (i % 2 == 1)
                {
                    top = top2;
                }
                else
                {
                    top = top1;
                }
                left = i * fWidth;
                g.DrawString(code.Substring(i, 1), f, b, left, top);
            }
            //画一个边框 边框颜色为Color.Black
            // g.DrawRectangle(new Pen(Color.Black, 0), 0, 0, image.Width - 1, image.Height - 1);
            g.Dispose();
            //产生波形
            image = TwistImage(image, true, 3, 0);
            return image;
        }
        #endregion

        #region 将创建好的图片输出到页面
        /// <summary>
        /// 将创建好的图片输出到页面
        /// </summary>
        /// <param name="code"></param>
        /// <param name="context"></param>
        public void CreateImageOnPage(string code, HttpContext context)
        {
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            Bitmap image = this.CreateImageCode(code);
            image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
            context.Response.ClearContent();
            context.Response.ContentType = "image/Jpeg";
            context.Response.BinaryWrite(ms.GetBuffer());
            ms.Close();
            ms = null;
            image.Dispose();
            image = null;
        }
        #endregion

        #region 生成随机字符码
        /// <summary>
        /// 生成随机字符码
        /// </summary>
        /// <param name="codeLen"></param>
        /// <returns></returns>
        public string CreateVerifyCode(int codeLen)
        {
            if (codeLen == 0)
            {
                codeLen = Length;
            }

            string[] arr = CodeSerial.Split(',');

            string code = "";

            int randValue = -1;

            Random rand = new Random(unchecked((int)DateTime.Now.Ticks));

            for (int i = 0; i < codeLen; i++)
            {
                randValue = rand.Next(0, arr.Length - 1);

                code += arr[randValue];
            }

            return code;
        }
        public string CreateVerifyCode()
        {
            return CreateVerifyCode(0);
        }
        #endregion

        #region 生成汉字字符
        /// <summary>
        /// 生成汉字字符
        /// </summary>
        /// <returns></returns>
        public char CreateZhChar()
        {
            //若提供了汉字集，查询汉字集选取汉字
            //if (ChineseChars.Length > 0)
            //{
            //    return ChineseChars[rnd.Next(0, ChineseChars.Length)];
            //}
            //若没有提供汉字集，则根据《GB2312简体中文编码表》编码规则构造汉字
            //else
            //{
            Random rnd = new Random();
            byte[] bytes = new byte[2];

            //第一个字节值在0xb0, 0xf7之间
            bytes[0] = (byte)rnd.Next(0xb0, 0xf8);
            //第二个字节值在0xa1, 0xfe之间
            bytes[1] = (byte)rnd.Next(0xa1, 0xff);

            //根据汉字编码的字节数组解码出中文汉字
            string str1 = System.Text.Encoding.GetEncoding("gb2312").GetString(bytes);

            return str1[0];
            //}
        }
        #endregion
    }
}
